[Plagioclase feldspar]

[Metatorbernite]

GEOLOGIC VALUES

Although the emphasis in this pamphlet has been on the recognition of Missouri rocks and minerals, it is not out of order to consider the broad values that they contribute to our civilization. Their use as building materials has been noted, but it should be further recognized that as our timber is being rapidly depleted more and more structures will be built out of earth materials. Missouri possesses a wealth of beautiful limestone that is serviceable and readily quarried. Where limestone is not near, there is usually shale or glacial clay which can be used in the manufacture of brick and tile. Permanency will be the keynote of the rock and ceramic structures. Gravel and sand are abundant in Missouri for concrete and other varied uses.

The soil is Missouri’s most valuable earth material. Hundreds to thousands of years of normal weathering are required to develop the rocks and minerals and texture of the inorganic fraction of the soil. We should preserve it and prevent disastrous soil erosion.

Aside from these more tangible values, a fascinating and instructive hobby can be made of collecting, arranging, and studying rocks and minerals. One gains a fuller understanding and appreciation of nature from their study. The orderliness, constancy, and interrelation within the rock and mineral “world” is a restful contrast to the one which man often keeps in turmoil. The beauty of a glistening crystal or a polished mineral or stone is as inspiring as a lovely flower, yet it lasts and lasts through centuries, a veritable “rock of ages.”

Suggested Collateral Reading Material

Books on Rocks and Minerals

How to Know the Minerals and Rocks, by Pearl; publisher, McGraw-Hill Book Co., New York.

A Field Guide to Rocks and Minerals, by Pough; publisher, Houghton, Mifflin Co., Boston.